The present invention relates to ventilation and to a supply-air device designed to be applied in a wall opening.
EP-B1-0 694 151 shows a method and a device for introducing ventilation air into a ventilated space by supplying air from a supply-air device downwardly along a wall, the air thereafter following the wall down due to the Coanda effect, being deflected at the floor and then spreading along the floor, whereupon air in the ventilated space is removed in the ceiling zone. The supply-air device is applied on the wall with its air passage vertical and its supply-air outlet directed downwardly.
The object of the invention is to provide an improved supply-air device on a wall, of the type permitting air to be supplied to a ventilated space at a distance above floor level and to subsequently flow downwardly along the wall due to the Coanda effect, being thereafter deflected and spread out over the floor.
The object of the invention is fulfilled by the invention having acquired the features defined in the claims. A suitable placing for a supply-air device of the present type is achieved by arranging said device in a preferably rectangular wall opening placed about 30-160 cm, preferably 70-120 cm above the floor, either in an outer wall or a partition wall. Also arranging this supply-air device with guiding surfaces that give the air flow a relatively narrow angle from the wall down towards the floor utilizes the Coanda effect according to which the flow of air has a tendency to attach itself to and accelerate down along the wall towards the floor. Thanks to this acceleration the clean air supplied at floor level is spread extremely well. The air supplied gradually mixes with and displaces the xe2x80x9cusedxe2x80x9d air from floor level and up through the room to an exhaust-air device near the ceiling so that the entire room is ventilated in an optimal manner. The configuration of the supply-air device comprises a recess so that the device can be inserted in the wall opening and displaced vertically over the wall part, after which the device is secured. The device is thus assembled after the wall part is in place, by sawing a rectangular opening in the wall and then fitting the device. The device may either be made in one piece or as two separate parts in the form of an upper and a lower part. To achieve optimal air flow down towards the floor the angle between the vertical plane and the control device of the supply-air device shall be within the interval 10xc2x0-45xc2x0, preferably 20xc2x0-25xc2x0. The control device extends in the wall section from one wall part to the inside of the other, opposite wall part in order to limit the space between the wall parts and obtain deflection of air entering from above and passing out through the opening. The inner, upper end of the lower part of the supply-air device is preferably provided with a flexible contact edge against the opposite wall part. If the upper and lower valve parts of the supply-air device are connected with end pieces, a suitable embodiment comprises allowing a supply-air duct to be connected to the inlet side of the supply-air device. The supply-air device is also provided with a damper to regulate the amount of fresh air supplied by adjusting the throttling in the device via an actuator. The wall opening may be a shape other than rectangular, e.g. circular or oval, depending on the aesthetic design of the supply-air device.